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api/I2CSlave.h@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Initial commit on mbed-dev



Replaces mbed-src (now inactive)

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bogdanm 0:9b334a45a8ff 1 /* mbed Microcontroller Library
bogdanm 0:9b334a45a8ff 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 0:9b334a45a8ff 3 *
bogdanm 0:9b334a45a8ff 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 0:9b334a45a8ff 5 * you may not use this file except in compliance with the License.
bogdanm 0:9b334a45a8ff 6 * You may obtain a copy of the License at
bogdanm 0:9b334a45a8ff 7 *
bogdanm 0:9b334a45a8ff 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 0:9b334a45a8ff 9 *
bogdanm 0:9b334a45a8ff 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 0:9b334a45a8ff 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 0:9b334a45a8ff 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 0:9b334a45a8ff 13 * See the License for the specific language governing permissions and
bogdanm 0:9b334a45a8ff 14 * limitations under the License.
bogdanm 0:9b334a45a8ff 15 */
bogdanm 0:9b334a45a8ff 16 #ifndef MBED_I2C_SLAVE_H
bogdanm 0:9b334a45a8ff 17 #define MBED_I2C_SLAVE_H
bogdanm 0:9b334a45a8ff 18
bogdanm 0:9b334a45a8ff 19 #include "platform.h"
bogdanm 0:9b334a45a8ff 20
bogdanm 0:9b334a45a8ff 21 #if DEVICE_I2CSLAVE
bogdanm 0:9b334a45a8ff 22
bogdanm 0:9b334a45a8ff 23 #include "i2c_api.h"
bogdanm 0:9b334a45a8ff 24
bogdanm 0:9b334a45a8ff 25 namespace mbed {
bogdanm 0:9b334a45a8ff 26
bogdanm 0:9b334a45a8ff 27 /** An I2C Slave, used for communicating with an I2C Master device
bogdanm 0:9b334a45a8ff 28 *
bogdanm 0:9b334a45a8ff 29 * Example:
bogdanm 0:9b334a45a8ff 30 * @code
bogdanm 0:9b334a45a8ff 31 * // Simple I2C responder
bogdanm 0:9b334a45a8ff 32 * #include <mbed.h>
bogdanm 0:9b334a45a8ff 33 *
bogdanm 0:9b334a45a8ff 34 * I2CSlave slave(p9, p10);
bogdanm 0:9b334a45a8ff 35 *
bogdanm 0:9b334a45a8ff 36 * int main() {
bogdanm 0:9b334a45a8ff 37 * char buf[10];
bogdanm 0:9b334a45a8ff 38 * char msg[] = "Slave!";
bogdanm 0:9b334a45a8ff 39 *
bogdanm 0:9b334a45a8ff 40 * slave.address(0xA0);
bogdanm 0:9b334a45a8ff 41 * while (1) {
bogdanm 0:9b334a45a8ff 42 * int i = slave.receive();
bogdanm 0:9b334a45a8ff 43 * switch (i) {
bogdanm 0:9b334a45a8ff 44 * case I2CSlave::ReadAddressed:
bogdanm 0:9b334a45a8ff 45 * slave.write(msg, strlen(msg) + 1); // Includes null char
bogdanm 0:9b334a45a8ff 46 * break;
bogdanm 0:9b334a45a8ff 47 * case I2CSlave::WriteGeneral:
bogdanm 0:9b334a45a8ff 48 * slave.read(buf, 10);
bogdanm 0:9b334a45a8ff 49 * printf("Read G: %s\n", buf);
bogdanm 0:9b334a45a8ff 50 * break;
bogdanm 0:9b334a45a8ff 51 * case I2CSlave::WriteAddressed:
bogdanm 0:9b334a45a8ff 52 * slave.read(buf, 10);
bogdanm 0:9b334a45a8ff 53 * printf("Read A: %s\n", buf);
bogdanm 0:9b334a45a8ff 54 * break;
bogdanm 0:9b334a45a8ff 55 * }
bogdanm 0:9b334a45a8ff 56 * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
bogdanm 0:9b334a45a8ff 57 * }
bogdanm 0:9b334a45a8ff 58 * }
bogdanm 0:9b334a45a8ff 59 * @endcode
bogdanm 0:9b334a45a8ff 60 */
bogdanm 0:9b334a45a8ff 61 class I2CSlave {
bogdanm 0:9b334a45a8ff 62
bogdanm 0:9b334a45a8ff 63 public:
bogdanm 0:9b334a45a8ff 64 enum RxStatus {
bogdanm 0:9b334a45a8ff 65 NoData = 0,
bogdanm 0:9b334a45a8ff 66 ReadAddressed = 1,
bogdanm 0:9b334a45a8ff 67 WriteGeneral = 2,
bogdanm 0:9b334a45a8ff 68 WriteAddressed = 3
bogdanm 0:9b334a45a8ff 69 };
bogdanm 0:9b334a45a8ff 70
bogdanm 0:9b334a45a8ff 71 /** Create an I2C Slave interface, connected to the specified pins.
bogdanm 0:9b334a45a8ff 72 *
bogdanm 0:9b334a45a8ff 73 * @param sda I2C data line pin
bogdanm 0:9b334a45a8ff 74 * @param scl I2C clock line pin
bogdanm 0:9b334a45a8ff 75 */
bogdanm 0:9b334a45a8ff 76 I2CSlave(PinName sda, PinName scl);
bogdanm 0:9b334a45a8ff 77
bogdanm 0:9b334a45a8ff 78 /** Set the frequency of the I2C interface
bogdanm 0:9b334a45a8ff 79 *
bogdanm 0:9b334a45a8ff 80 * @param hz The bus frequency in hertz
bogdanm 0:9b334a45a8ff 81 */
bogdanm 0:9b334a45a8ff 82 void frequency(int hz);
bogdanm 0:9b334a45a8ff 83
bogdanm 0:9b334a45a8ff 84 /** Checks to see if this I2C Slave has been addressed.
bogdanm 0:9b334a45a8ff 85 *
bogdanm 0:9b334a45a8ff 86 * @returns
bogdanm 0:9b334a45a8ff 87 * A status indicating if the device has been addressed, and how
bogdanm 0:9b334a45a8ff 88 * - NoData - the slave has not been addressed
bogdanm 0:9b334a45a8ff 89 * - ReadAddressed - the master has requested a read from this slave
bogdanm 0:9b334a45a8ff 90 * - WriteAddressed - the master is writing to this slave
bogdanm 0:9b334a45a8ff 91 * - WriteGeneral - the master is writing to all slave
bogdanm 0:9b334a45a8ff 92 */
bogdanm 0:9b334a45a8ff 93 int receive(void);
bogdanm 0:9b334a45a8ff 94
bogdanm 0:9b334a45a8ff 95 /** Read from an I2C master.
bogdanm 0:9b334a45a8ff 96 *
bogdanm 0:9b334a45a8ff 97 * @param data pointer to the byte array to read data in to
bogdanm 0:9b334a45a8ff 98 * @param length maximum number of bytes to read
bogdanm 0:9b334a45a8ff 99 *
bogdanm 0:9b334a45a8ff 100 * @returns
bogdanm 0:9b334a45a8ff 101 * 0 on success,
bogdanm 0:9b334a45a8ff 102 * non-0 otherwise
bogdanm 0:9b334a45a8ff 103 */
bogdanm 0:9b334a45a8ff 104 int read(char *data, int length);
bogdanm 0:9b334a45a8ff 105
bogdanm 0:9b334a45a8ff 106 /** Read a single byte from an I2C master.
bogdanm 0:9b334a45a8ff 107 *
bogdanm 0:9b334a45a8ff 108 * @returns
bogdanm 0:9b334a45a8ff 109 * the byte read
bogdanm 0:9b334a45a8ff 110 */
bogdanm 0:9b334a45a8ff 111 int read(void);
bogdanm 0:9b334a45a8ff 112
bogdanm 0:9b334a45a8ff 113 /** Write to an I2C master.
bogdanm 0:9b334a45a8ff 114 *
bogdanm 0:9b334a45a8ff 115 * @param data pointer to the byte array to be transmitted
bogdanm 0:9b334a45a8ff 116 * @param length the number of bytes to transmite
bogdanm 0:9b334a45a8ff 117 *
bogdanm 0:9b334a45a8ff 118 * @returns
bogdanm 0:9b334a45a8ff 119 * 0 on success,
bogdanm 0:9b334a45a8ff 120 * non-0 otherwise
bogdanm 0:9b334a45a8ff 121 */
bogdanm 0:9b334a45a8ff 122 int write(const char *data, int length);
bogdanm 0:9b334a45a8ff 123
bogdanm 0:9b334a45a8ff 124 /** Write a single byte to an I2C master.
bogdanm 0:9b334a45a8ff 125 *
bogdanm 0:9b334a45a8ff 126 * @data the byte to write
bogdanm 0:9b334a45a8ff 127 *
bogdanm 0:9b334a45a8ff 128 * @returns
bogdanm 0:9b334a45a8ff 129 * '1' if an ACK was received,
bogdanm 0:9b334a45a8ff 130 * '0' otherwise
bogdanm 0:9b334a45a8ff 131 */
bogdanm 0:9b334a45a8ff 132 int write(int data);
bogdanm 0:9b334a45a8ff 133
bogdanm 0:9b334a45a8ff 134 /** Sets the I2C slave address.
bogdanm 0:9b334a45a8ff 135 *
bogdanm 0:9b334a45a8ff 136 * @param address The address to set for the slave (ignoring the least
bogdanm 0:9b334a45a8ff 137 * signifcant bit). If set to 0, the slave will only respond to the
bogdanm 0:9b334a45a8ff 138 * general call address.
bogdanm 0:9b334a45a8ff 139 */
bogdanm 0:9b334a45a8ff 140 void address(int address);
bogdanm 0:9b334a45a8ff 141
bogdanm 0:9b334a45a8ff 142 /** Reset the I2C slave back into the known ready receiving state.
bogdanm 0:9b334a45a8ff 143 */
bogdanm 0:9b334a45a8ff 144 void stop(void);
bogdanm 0:9b334a45a8ff 145
bogdanm 0:9b334a45a8ff 146 protected:
bogdanm 0:9b334a45a8ff 147 i2c_t _i2c;
bogdanm 0:9b334a45a8ff 148 };
bogdanm 0:9b334a45a8ff 149
bogdanm 0:9b334a45a8ff 150 } // namespace mbed
bogdanm 0:9b334a45a8ff 151
bogdanm 0:9b334a45a8ff 152 #endif
bogdanm 0:9b334a45a8ff 153
bogdanm 0:9b334a45a8ff 154 #endif